What happened with an idea about an integrated plugin/themes marketplace in plugin/themes directory? Like Free/Freemium/Paid sections? It’s a win-win-win situation: stream of income to the CP, convenience to the CP users and a perfect solution to paid plugin/theme developers. If you charge a modest 20% for a transaction, it will be more than enough to fund not only development.
To compete with paid support providers, plugin developers, theme developers, hosting providers is a bad idea IMHO. They should be supporters, not competitors.